During many surgical operations it is necessary to provide extracorporeal blood circulation in a circuit which comprises a pump and several other blood treatment devices, such as an oxygenator, a heat exchanger, at least one filter, and a reservoir bag.
The space available in the vicinity of the operating field is notoriously very limited, and therefore the aim of the present invention is to provide a pulsating pumping unit for a fluid, particularly blood, which is highly compact and is suitable to be easily integrated with the other devices of the extracorporeal circuit, so as to be able to achieve maximum reduction of space occupation.